Apparatus and method for diagnosis of catalyst performance
US6301881A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 2000 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Feb 18, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method and apparatus that converts time-resolved sensor signals into frequency domain signals using Fast Fourier Transforms and power spectral densities. A signal, as a means to assess catalyst performance such as a signal based on sensing oxygen concentration in motor vehicle exhaust in accordance with the present invention is in the time domain and has multiple components at different frequencies. The use of Fast Fourier Transforms isolates the various spectral density which arise from different frequency components of the complex time domain signal. The analysis has been found to be substantially independent of operating conditions. The power spectral density has found to be a precise indication of oxygen storage and release of the catalyst and catalyst performance. The catalyst performance can be signaled to the vehicle operator for on board diagnostics (OBD) of the catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.